package com.hmdp.service.impl;

import cn.hutool.core.util.BooleanUtil;
import cn.hutool.core.util.StrUtil;
import cn.hutool.json.JSONObject;
import cn.hutool.json.JSONUtil;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.dto.Result;
import com.hmdp.entity.Shop;
import com.hmdp.mapper.ShopMapper;
import com.hmdp.service.IShopService;
import com.hmdp.utils.CacheClient;
import com.hmdp.utils.RedisConstants;
import com.hmdp.utils.RedisData;
import com.hmdp.utils.SystemConstants;
import org.springframework.data.geo.Distance;
import org.springframework.data.geo.GeoResult;
import org.springframework.data.geo.GeoResults;
import org.springframework.data.geo.Point;
import org.springframework.data.redis.connection.RedisGeoCommands;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.domain.geo.GeoReference;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import javax.annotation.Resource;
import java.time.LocalDateTime;
import java.util.*;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;

import static com.hmdp.utils.RedisConstants.*;


@Service
public class ShopServiceImpl extends ServiceImpl<ShopMapper, Shop> implements IShopService {


    @Resource
    private StringRedisTemplate stringRedisTemplate;

    @Resource
    private CacheClient cacheClient;

    @Override
    public Result queryById(Long id) {

        // 1.缓存穿透
        // (id2)->{getById(id)} 简写成 this :: getById
        Shop shop = cacheClient.queryWithPassThrough(CACHE_SHOP_KEY, id, Shop.class,
                this::getById, CACHE_SHOP_TTL, TimeUnit.MINUTES);

        // 逻辑过期解决缓存击穿
//        Shop shop = cacheClient.queryWithLogicalExpire(CACHE_SHOP_KEY, id, Shop.class,
//                this::getById, 20L, TimeUnit.SECONDS);
        if (shop == null) {
            return Result.fail("店铺不存在！");
        }
        // 4.返回商铺信息
        return Result.ok(shop);
    }

    public void saveShopRedis(Long id, Long expireSeconds) {
        // 1. 查询店铺信息
        Shop shop = getById(id);
        // 2. 封装逻辑过期
        RedisData redisData = new RedisData();
        redisData.setData(shop);
        redisData.setExpireTime(LocalDateTime.now().plusSeconds(expireSeconds));
        // 3. 写入Redis
        stringRedisTemplate.opsForValue().set(CACHE_SHOP_KEY + id,
                JSONUtil.toJsonStr(redisData));
    }

    /**
     * 添加事务，出现异常，回滚
     *
     * @param shop
     * @return
     */
    @Override
    @Transactional
    public Result update(Shop shop) {
        // 1.更新数据库
        Long id = shop.getId();
        if (id == null) {
            return Result.fail("店铺id不能为空");
        }
        updateById(shop);
        // 2.删除缓存
        stringRedisTemplate.delete(CACHE_SHOP_KEY + id);
        return Result.ok();
    }

    @Override
    public Result queryShopByType(Integer typeId, Integer current, Double x, Double y) {
        // 1. 判断是否根据坐标查询
        if (x == null || y == null) {
            Page<Shop> page = query().eq("type_id", typeId)
                    .page(new Page<>(current, SystemConstants.MAX_PAGE_SIZE));
            return Result.ok(page.getRecords());
        }
        // 2. 计算分页参数
        int from = (current - 1) * SystemConstants.MAX_PAGE_SIZE;
        int end = current * SystemConstants.MAX_PAGE_SIZE;
        // 3. 查询redis，按照距离排序，分页；结果：shopId、distance
        String key = SHOP_GEO_KEY + typeId;
        GeoResults<RedisGeoCommands.GeoLocation<String>> results =
                stringRedisTemplate.opsForGeo()
                        .search(
                                key,
                                GeoReference.fromCoordinate(x, y),
                                new Distance(5000),
                                RedisGeoCommands
                                        .GeoSearchCommandArgs
                                        .newGeoSearchArgs()
                                        .includeDistance()
                                        .limit(end)
                        );
        // 4. 解析出id
        if (results == null) {
            return Result.ok(Collections.emptyList());
        }
        List<GeoResult<RedisGeoCommands.GeoLocation<String>>> list = results.getContent();
        if (list.size() <= from) {
            return Result.ok(Collections.emptyList());
        }
        // 4.1 截取 from -> end 的部分
        List<Long> ids = new ArrayList<>(list.size());
        Map<String, Distance> distanceMap = new HashMap<>(list.size());
        list.stream().skip(from).forEach(result -> {
            // 获取店铺id
            String shopIdStr = result.getContent().getName();
            ids.add(Long.valueOf(shopIdStr));
            // 获取距离
            Distance distance = result.getDistance();
            distanceMap.put(shopIdStr, distance);
        });
        // 5. 根据id查询shop,保证有序

        String idStr = StrUtil.join(",", ids);
        List<Shop> shops = query().in("id", ids).last("ORDER BY FIELD(id," + idStr + ")").list();
        for (Shop shop : shops) {
            shop.setDistance(distanceMap.get(shop.getId().toString()).getValue());
        }

        // 返回
        return Result.ok(shops);
    }
}
